The present invention relates to scrapers mounted on road vehicles such as snow plows, graders and the like, and more particularly, to deflecting retractable side wing assemblies used for increasing the working span of traditional scrapers.
It is well known that during winter, in the few hours following a considerable accumulation of snow, an important snow-clearing operation of the road network of the affected area must be put into gears. This operation must be done quickly for economic reasons, and it must also be done safely.
One way of clearing the streets is by adapting a snowplow structure in front of a vehicle. Often, a lateral extension of this structure, or side wing, increases the reach of the area scraped by the snowplow. When the vehicle is not being used for its snowplowing capabilities, the side wing may sometimes be lifted up vertically on the side of the vehicle to reduce its span on the road.
When an obstacle is in the path of the side wing, the driver usually has two choices to avoid it. He may choose to maneuver his vehicle around the obstacle, often by bringing his vehicle to cross dangerously into the next lane, which may also sometimes have the traffic going the opposite way increasing the chances of having a face-to-face hit with another vehicle. Alternatively the driver may, if the option is given to him, use the lifting device to raise upwardly the side wing. By quickly engaging this motion, the driver will lose precious time by slowing down and may temporarily and dangerously hold his steering wheel with only one hand while the other activates the lifting device.
It may also happens that an obstacle such as a railing or a shoulder, for example, in the path of the side wing is not seen on time, or that it may be hidden and not be detected at all by the driver. In such cases, a security shear pin properly installed at the attachment point between the side wing and the vehicle will break upon impact between the obstacle and the side wing. The driver must then lose precious time by stopping his snowplow and get the security pin replaced. In all cases though, important damages may be inflicted upon the side wing and some elements of the structure of the snowplow, reducing its useful lifetime, as well as causing damages on the obstacle itself that often needs to be replaced thus incurring extra-expenses.
Side wing assembly has been disclosed in the prior art in U.S. Pat. No. 4,969,280 issued on Nov. 13, 1990 to D. Thorneloe. In this invention, the damping system is solely located on the pair of parallel arms, hence cannot easily be protected against outside elements, and may not be easily adaptable as a kit to existing side wing blade assembly, where a complete new attachment system would be required.
It shall also be noted that in the case of the latter invention, when the side blade hits an obstacle, the deflection towards the vehicle is minimal, as per the telescopic distance of the first section and the longer section of the parallel arms, as well as the coil spring elongation. Basically, as soon as one of these mechanisms is fully contracted (and because the fluid ram is fully retracted when the blade engages the ground surface), the assembly will tend to upwardly lift the blade, hence stopping the snow removal action. Therefore, this deflection is not planned to be solely within a horizontal plane and keeping on removing the snow. Furthermore, the fact that both front and rear extremities of the damping assembly are pivotally mounted reduces its efficiency and increases the risk of being subject to frequent damages.
It is a general object of the present invention to provide a deflecting retractable side wing assembly that obviates the above mentioned disadvantages.
Another object of the present invention is to provide a deflecting retractable side wing assembly that is efficient and simple to manufacture.
A further object of the present invention is to provide a deflecting retractable side wing assembly that is easy to operate with and that can be adjustable to resist different shock levels.
Still another object of the present invention is to provide a deflecting retractable side wing assembly that can be installed as a kit on existing side scrapers to make the latter deflecting upon hits with rigid obstacles.
Still a further object of the present invention is to provide a deflecting retractable side wing assembly that is easily integrated with different types of snow plow structures.
Yet another object of the present invention is to provide a deflecting retractable side wing assembly that can be, permanently or not, voluntarily partially deflected by an operator to avoid hitting rigid obstacles with the free end of the retractable side wing and/or limit the motion of the same within a partially and a fully deflected positions.
Yet a further object of the present invention is to provide a deflecting retractable side wing assembly that includes a resilient member at its free end to hit obstacles, when unavoidable, without damaging the free end of the side wing itself.
Other objects and advantages of the present invention will become apparent from a careful reading of the detailed description provided herein, with appropriate reference to the accompanying drawings.
According to one aspect of the present invention, there is provided a retractable side wing assembly adapted to be mounted on a side of a road vehicle for clearing snow off a road surface, said side wing assembly comprising a scraper having a frontward end pivotally secured to said side of said vehicle and a rearwardly and outwardly extending free end, a retracting member having a first end rotatably secured to a moving part of a shock absorbing device and a second end rotatably secured either to said side of said vehicle rearwardly of said scraper or to said scraper in proximity of said free end, and a fixed part of said shock absorbing device rigidly secured either to said scraper in proximity of said frontward end or to said vehicle rearwardly of said scraper respectively, said shock absorbing device including an absorber member rigidly secured to both said moving and fixed parts thereof, said shock absorbing device allowing for automatic rearward deflection of said scraper pivoting around said frontward end from a standard position to a fully deflected position when hitting an obstacle and said retracting member allowing for retracting and extracting said retractable assembly in up and down position along said side of said vehicle respectively.
Preferably, the moving part of said shock absorbing device is slidably secured to said fixed part.
Preferably, the said scraper, shock absorbing device and retracting member are generally laid within a same horizontal plane.
Preferably, the second end of said retracting member is rotatably secured to said side of said vehicle rearwardly of said scraper and said fixed part of said shock absorbing device being rigidly secured to said scraper in proximity of said frontward end, said moving part being generally rearwardly of and linearly moving relative to said fixed part in a direction generally parallel to said scraper.
Preferably, the shock absorbing device includes a guiding member for guiding said moving part slidably mounted on said fixed part.
Preferably, the moving part of said shock absorbing device is a carriage and said guiding member being at least one roller rotatably mounted on said carriage for rollingly engaging a corresponding guiding rail of said fixed part.
Preferably, the absorber member is a damping member, such as a typical pneumatic damping suspension.
Preferably, the retracting member and said scraper define within a generally horizontal plane an internal angle greater than 90 degrees.
Preferably, the shock absorbing device is a kit retrofitted on said scraper and retracting member, the latter two having been previously assembled together on said side of said vehicle.
Preferably, the retractable assembly further comprises a hydraulic ram actuator having a first extremity pivotally mounted to said free end of said scraper outwardly of said moving part of said shock absorbing device and a second extremity abutting said moving part, said actuator pushing said moving part toward said fixed part in a partially deflected position of said scraper when activated by an operator via a hydraulic network, thus limiting free automatic deflection of said scraper between said partially deflected and said fully deflected positions.
Preferably, the retractable assembly further comprises a resilient member secured to said free end of said scraper and slightly extending out of the same and adapted to take lateral hit instead of said free end to protect the same from lateral vertical obstacles.
Preferably, the resilient member includes at least one resilient roller made out of rubber type material and freely rotatably mounted on a generally vertical shaft rigidly supported by brackets secured to said free end of said scraper.
Alternatively, the second end of said retracting member being rotatably secured to said scraper in proximity of said free end of the same and said fixed part of said shock absorbing device being rigidly secured to said vehicle rearwardly of said scraper, said moving part being generally frontwardly of and linearly moving relative to said fixed part in a direction generally parallel to said side of said vehicle.
Accordingly, the retractable assembly preferably further comprises a hydraulic ram actuator having a first extremity pivotally mounted to said side of said vehicle frontwardly of said moving part of said shock absorbing device and a second extremity abutting said moving part, said actuator pushing said moving part toward said fixed part in a partially deflected position of said scraper when activated by an operator via a hydraulic network, thus limiting free automatic deflection of said scraper between said partially deflected and said fully deflected positions.